Reoperation rates after proximal femur fracture fixation with single and dual screw femoral nails: a systematic review and meta-analysis

PURPOSE: The purpose of this study was to investigate differences in aseptic reoperation rates between single or dual lag screw femoral nails,in the treatment of intertrochanteric fractures (ITF) in elderly patients. METHODS: Electronic databases were searched for RCTs and prospective cohort studies treating elderly ITF patients with a single or dual screw femoral nails. Data for aseptic reoperation rates between single screw, dual separated screw and dual integrated screw devices were pooled using a random-effects meta-analysis with 95% CIs. Pooled proportions were compared using a N-1 chi-squared test. Complications contributing to aseptic reoperation rates were extracted, and the contribution of cut-out and periprosthetic fracture as a proportion of reoperations was analysed using a negative binomial regression model. RESULTS: Forty-two (n = 42) studies were evaluated, including 2795 patients treated with a single screw device, 1309 patients treated with a dual separated screw device and 303 patients treated with a dual integrated screw device. There was no significant difference in aseptic reoperation rates between single and dual lag screw femoral nails of both separated and integrated lag screw designs. Moreover, complications of cut-out and periprosthetic fracture as a proportion of reoperations did not differ significantly between devices. CONCLUSION: The current evidence showed that aseptic reoperation rates were not significantly different between single and dual screw nails of a separated lag screw design. For dual integrated screw devices, due to insufficient evidence available, further high quality RCTs are required to allow for decisive comparisons with these newer devices.